Why does the acceptance of an answer not imply an upvote?

Question

It happens to see accepted answers that don't get any upvote. I am struggling understanding the meaning of this. According to Help Center, accepting an answer

simply means that the author received an answer that worked for them personally

while voting up an answer means that it is

helpful and well-researched.

Given this semantics, it seems clear to me that an accepted answer should deserve at least one upvote from the asker who accepted the answer. So, why does the acceptance of an answer not imply automatically one upvote from the asker? An autmoatic upvote from the asker accepting an answer seems to me absolutely coherent with the meaning of upvote and accepted answer.

I am aware of technical reasons that explain the existence of accepted answers without upvotes, for instance the fact that the asker should have at least 15 reputation to upvote, or that there is a limit of upvotes per day, but I think it is easy to overcome these technicalities. For instance, the automatic upvote from the asker accepting an answer might not be counted for the upvote limit or might not require 15 reputation, or might be valid if the asker has at least 15 reputation (and their upvote could be enabled the day after if they already reached the upvote limit).

This question is related to that one, even though I don't think it is a duplicate.

Answer 1

An answer can be technically correct without being particularly helpful or useful, and the question asker should be allowed to acknowledge that as well. For example, there was a question recently on main that amounted to "What is the Banach-Dieudonné theorem?" A 'correct' answer to that would be to state the theorem, copied probably from wikipedia or a text-book. A helpful answer would take that further and point out things of interest about the theorem, sources to learn more, and perhaps comment on the necessity of the hypotheses (which an answer to it did, in fact). The first answer, a blank theorem statement, is not worth an upvote for most people, but if it's the only answer provided then in the interests of site hygiene it should be accepted (and the asker should take away a lesson to phrase their question a little less narrowly).